Hoist the loop-invariant load out of the loop and call the other CheckMap function
BUG=none
TEST=none

Committed: https://code.google.com/p/v8/source/detail?r=13200

Review URL: https://codereview.chromium.org/11369014
Patch from Rajeev Krithivasan <rkrithiv@codeaurora.org>.

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@13253 ce2b1a6d-e550-0410-aec6-3dcde31c8c00